engine stall when driving

2003 FORD WINDSTAR

150,000 MILES • 3.8L • 6 CYL • FWD • AUTOMATIC

RICHARDGLADISH

MEMBER
4 POSTS

Engine stalls, mostly after sitting at a street light. Doesn't make any difference, going up a hill or making a turn. Lately it has stalled while driving at 50 miles an hour. This problem only happens when it is dry outside. If it is raining it doesn't give any problems. Also note that the engine will restart as soon as the ignition switch is turned off and then on again. I have replaced the cam and crankshaft sensors. Ran good for a few days (damp outside), now it is doing the same thing. Thought it might be the ignition switch, but why would it give a problem only on drier days. Live on west coast where their is always a lot of moisture.

Mar 26, 2017 at 6:16 AM

HMAC300

✓ASE Certified Mechanic
48,601 POSTS

try cleaning throttle plate on both sides and iac hole with choke cleaner then if it continues scan for codes and check fuel pressure with a gauge auto parts rent it. as it can be anything see link.
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Mar 26, 2017 at 1:24 PM

STEVE W.

✓ASE Certified Mechanic
15,200 POSTS

Sounds more like a bad ground connection, the water makes the connection damp and it works, when it dries out the connection fails and the engine shuts down. I would start by checking the grounds and connections from the engine to the body and battery to body first. Then check the power side as well. Check the ares around the ignition and throttle body. I'm doubtful it's a sensor as those would just fail if water got into them, they would work better when dried out.

I'm thinking this might not be easy to find because of the strange mode of failure.

Mar 26, 2017 at 2:24 PM

RICHARDGLADISH

MEMBER
4 POSTS

I've checked most of the grounds, I could have easily missed some. Need to add check engine light does not come on with the engine stalls.

Mar 26, 2017 at 5:02 PM

STEVE W.

✓ASE Certified Mechanic
15,200 POSTS

Yeah it isn't going to be an easy thing to trace. Finding the bad connection is going to be difficult with the number of connections. You might be able to narrow it down if you can figure out if it's spark or fuel that is dropping out. Maybe listen real close when it shuts down and see if you can hear the fuel pump.

Mar 26, 2017 at 6:43 PM

RICHARDGLADISH

MEMBER
4 POSTS

I did once a failure code, p001- fuel volume regulator open. maybe there is a fuel pressure issue?
going to drive it today and check battery voltages, raining out, might not have a problem. Also noticed the lights flickering at startup, built in regulator seem to be acting up.

Mar 27, 2017 at 6:38 AM

STEVE W.

✓ASE Certified Mechanic
15,200 POSTS

A pressure regulator issue could easily cause this issue if it is keeping the pressure too low. Or is changing the pressure at the wrong time.

Mar 27, 2017 at 8:23 AM

RICHARDGLADISH

MEMBER
4 POSTS

going to do some fuel pressure tests in the next couple days, will let you know results. Note I got a p0174 reading on my tester today.

Mar 27, 2017 at 6:10 PM

STEVE W.

✓ASE Certified Mechanic
15,200 POSTS

That would make sense. System lean would follow a bad regulator and cause stalling from a lean mix.

Mar 27, 2017 at 7:20 PM

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